Booting from ZFS root on MBR layout fails on ThinkPad X61s

[Sevan / Venture37]

Hi,
I decided to wipe away the disk in my X61s & start afresh with a new
install of FreeBSD-Current at the same time switching to root on ZFS
(previously /boot was on UFS).
I've been unsuccessful in being able get the system to boot, after
trying various combinations of
https://wiki.freebsd.org/RootOnZFS/ZFSBootPartition I switched back to
using the install menu option & just switching from GPT to MBR
(everything else as default).
Once install completes & the system reboots, the system hangs at a prompt.

I was pointed to a post regarding modifying partition ID's by Allan
Jude as there seems to have been an issue with ThinkPads & FreeBSD in
the past. This also didn't work & caused the system to reset.

What should be my next step for trying to debug this issue?


Sevan / Venture37